CTA Report, Draft 1, ISP Review - US Chemical Safety and Hazard ...

7.3 Line 405 Equipment Testing
CSB identified equipment on line 405 that required testing, including:
• Oven temperature controller.
• Gas piping and manifold components.
• Electrical components near the point of origin of the fire.
A CSB contractor tested these components. In some cases, fire and explosion damage prevented CSB
from drawing useful conclusions. Results of the testing are presented below and in Appendix C.
Holes for wiring in the burner temperature control box allowed fiberglass, dust, and oily material to enter
and accumulate on electrical connections. This debris may have contributed to the failure of the
temperature controller. CSB could not determine if this actually impacted the operation of the controller
because loss of electric power in the facility and failure of the backup battery erased the controller
memory. Therefore, no historical data were available regarding the operating temperatures of the oven
prior to or during the incident.
Line 405 distribution gas piping and oven manifold components were tested to determine whether they
released natural gas (Section 7.1.2.1 and Appendix C). No leaks were found that would have released gas
into the building.
Electrical components near the point of origin of the fire and explosion were tested to see if they were
ignition sources. No evidence was found in line 405 electrical boxes or associated wiring from the oven
oiling system that indicated they were a source of ignition.
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